1. Field of the Invention
The present invention relates to a station selector used for a color television receiver and the like, which is made capable of storing a position exclusive for a factory at the time of production at the factory.
2. Description of the Related Art
In a conventional station selector, a memory exclusive for a factory for storing data used for checking when it is checked whether station selecting operation is being performed properly or not at the time of production is not provided, and adjustment and has been performed at the factory by utilizing a memory exclusive for a market to be used in practice by an operator in station selecting operation after shipment of products.
A conventional station selector will be described hereafter with reference to the drawings.
FIG. 1 is a block diagram of a conventional station selector. In FIG. 1, a numeral 12 denotes a station selection indication input circuit, 16 thru 18 denote position memories exclusive for a market which store n pieces of (n: integer 1 and above) station selecting data (frequency data) for every position, 15 denotes a memory control circuit for write and read of station selecting data in each memory by controlling above-mentioned position memories 16 thru 18, 14 denotes a tuner for obtaining a picture image of a television receiver in practice, and 13 denotes a station selection control circuit for sending data obtained by controlling above-mentioned memory control circuit in accordance with a command of above-mentioned station selection indication input circuit 12 to the tuner 14.
The operation of a conventional station selector thus constructed will be described with reference to FIG. 1.
In FIG. 1, when a position selecting command arrives at the station selection indication input circuit 12 (selecting means not shown), the memory control circuit 15 reads station selecting data at a position 2 from a position memory 2 in accordance with the input thereof if the command is to select the position 2, the station selection control circuit 13 sends station selecting data thereof to the tuner 14, and a specific channel is selected in the tuner 14 from television broadcasting which is on the air for adjustment at the factory based on the station selecting data so that a selected channel is on a television receiver.
In above-described operation, however, electric wave presents bad electric wave condition sometimes in relation to factory facilities, which is unsuitable for adjustment in the factory with position data in an actual shipping state (data for selecting respective channels on the air in the market). Thus, it is required to write exclusive position data for adjusting in the factory (data for selecting respective channels of television broadcasting which is on the air for the purpose of adjustment at the factory only). However, when shipment is made with position data in the factory remaining as it is, troubles may be caused in the actual market this time (for example, because there are also station selecting data for a channel which is not broadcast in an ordinary market). In order to make up for such a contradiction, rewriting to position data for selecting television broadcasting channels on the air practically in the market has been heretofore made again at the time of shipment. Otherwise, position memories more than required or station selecting data for channels which are not in use (not in the air) depending on the market to which shipment is made have been prepared in the factory.